Systemic nickel allergy syndrome: nosologic framework and usefulness of diet regimen for diagnosis.

Systemic (gastrointestinal and skin) reactions to ingestion of nickel rich foods in patients with nickel allergic contact dermatitis characterize Systemic Nickel Allergy Syndrome (SNAS). The objective of the study was to describe the nosologic framework of the syndrome and to compare sensibility and specificity for SNAS diagnosis between two different low nickel diets - BraMa-Ni and the usually prescribed list of forbidden foods - along with patient adherence to diet. One hundred forty-five patients with suspected SNAS (by history and benefit from nickel dietary restrictions) were selected and orally challenged with nickel for a definite diagnosis. Specificity and sensibility of the diets were calculated in relation to the results of nickel challenges. The nosologic framework of SNAS was deduced from the clinical pictures of 98 patients with positive nickel challenge and characterized essentially by skin and gastrointestinal symptoms, whereas all other symptoms (dizziness, headache etc.) were never elicited by the oral nickel challenge. The specificity and sensibility of BraMa-Ni in detecting SNAS were significantly higher than the forbidden food list diet, with an excellent patient adherence. Therefore, BraMa-Ni diet can be prescribed for the treatment of the syndrome other than for the diagnosis, the gold standard of which remains the oral nickel challenge.

Italian study on buckwheat allergy: prevalence and clinical features of buckwheat-sensitized patients in Italy.

Buckwheat allergy is considered a rare food allergy outside of Asia. In Europe, buckwheat has been described mainly as a hidden allergen. Data on the prevalence of buckwheat hypersensitivity in non-Asian countries is very poor. The aim of this multicenter study was to evaluate the prevalence of buckwheat sensitization and its association with other sensitizations among patients referred to allergy clinics in different geographic areas of Italy. All patients referred to 18 Italian allergy clinics from February through April 2011 were included in the study and evaluated for sensitization to buckwheat and other allergens depending on their clinical history. A total of 1,954 patients were included in the study and 61.3 percent of them were atopic. Mean prevalence of buckwheat sensitization was 3.6 percent with significant difference between Northern (4.5 percent), Central (2.2 percent) and Southern (2.8 percent) regions. This is, to our knowledge, the largest epidemiological survey on buckwheat allergy reported outside of Asia. Buckwheat is an emerging allergen in Italy, being more frequently associated to sensitization in Northern regions.

Dose-dependent clinical and immunological efficacy of sublingual immunotherapy with mite monomeric allergoid.

Sublingual immunotherapy with monomeric carbamylated allergoid (LAIS) is an effective and well tolerated treatment of respiratory allergy. The aim of the present study was to correlate the efficacy of two maintenance doses (1000 AU vs 3000 AU) of LAIS with the immunological modulation of allergen-driven Th1, Th2 and T regulatory cytokines produced in vitro by PBMCs, in patients suffering from mite allergic rhinitis. Forty-eight consecutive patients with mite allergic rhinitis were recruited. Patients were randomly assigned to group A (n=24) or group B (n=24), respectively receiving 1000 AU or 3000 AU weekly during one-year maintenance phase. Each patient was evaluated for rhinitis severity (ARIA protocol), and for drug consumption at the time of the inclusion and after 6 and 12 months of treatment. Patients were also asked to report the perceived severity of the disease and the tolerability of the treatment in a visual analogical scale (VAS). Before and at the end of the treatment allergen-driven release of cytokines by PBMCs in vitro was measured. After 1-year treatment, a statistically significant reduction of all clinical parameters was observed in all patients, associated with reduction of IL-4 and increase of INF-γ secreted in vitro by mite-challenged PBMCs. Notably, the group treated with the higher dose showed significantly better clinical and immunological results. The efficacy of LAIS is correlated to the immune modulation in a clear dose-dependent effect.

The persistence of allergen exposure favors pulmonary function decline in workers with allergic occupational asthma.

BACKGROUND: In asthmatics, a rapid decline in pulmonary function is observed, likely as a consequence of airways remodeling. Persistence of allergen exposure in patients with occupational asthma (OA) maintains chronic bronchial inflammation, resulting in a more severe lung function decline. Few studies were performed on the effects of allergen exposure cessation. OBJECTIVE: This study aims at evaluating the influence of allergen exposure cessation on respiratory decline in allergic asthmatic workers. METHODS: Two groups of workers with allergic OA were selected. The first group (30 workers) changed job after the diagnosis and was no more exposed to sensitizing allergens, and the second group (28 subjects) did not and, as a consequence of preventive measures in the work place, was exposed to a lower level of allergens. All were treated with conventional therapy, according to GINA protocols. FEV1 changes during a 12-year period were evaluated. RESULTS: Despite pharmacological therapy, the pulmonary function decay slope was steeper in workers continuously exposed to the sensitizing agent (even at reduced level) than in those with a complete cessation of exposure: final FEV1 loss was 512.5 ± 180 ml versus 332.5 ± 108 ml, respectively. The difference became significant after 4 years from the cessation of the exposure. CONCLUSIONS: The study shows that the cessation of the exposure to allergen in the work place appears the most effective measure in limiting pulmonary function decline in asthmatic workers and underlines the importance of allergic risk assessment and control in the management of occupational asthma.

Environmental pollution and asthma.

Clinical evidences and epidemiological studies show that allergic pathologies of the respiratory tract are increasing in the world areas with high pollution impact, demonstrating how many polluting substances favor both allergic sensitization and the bronchial inflammatory changes characteristic of asthma. It has been shown that asthma, as many other diseases, is a complex interaction between genetic predisposition and environmental stimuli that results in clinical expression of various phenotypes of asthma: allergic, intrinsic etc. Many pollutants have such a potential. Diesel exhaust particles (DEP) can favor allergic sensitization, induce acute asthma attacks and increase bronchial reactivity, acting both on allergen, on bronchial mucosa and on immune cells. In fact, DEP can favor B lymphocytes to shift to a production of IgE and T cells to produce Th2 cytokines. Asthma can be also induced by high exposure to many other substances as NO2 and first of all ozone (O3): strong oxidizing substance that is synthesized, in absence of ventilation, by photochemical reaction due to the combination of ultraviolet sun radiation on exhaust gases as NO2 and hydrocarbons. Ozone is abundant in cities with minimal concentration in the morning gradually increasing during the day until maximal levels in the afternoon and then decreasing during the night. Epidemiological studies show that the number of access to hospital for acute asthma and even the use of bronchodilator by asthmatics increase during the high level periods when Ozone constitute almost 90 percent of the total oxidants in the environment. Particulate matter of very small diameter have a crucial role in favoring asthma attacks, and smaller the substance deeper the penetration in the bronchial tree, with an inflammatory reaction in the peripheral bronchial mucosa characterized by increased vessel permeability, mucosal edema, inflammatory mediator production by damaged epithelium and inflammatory cells that determines acutely a high narrowing of the bronchial lumen and in a long period favor airways remodeling and a rapid decline of respiratory function.

T regulatory cells in allergy.

The progressive understanding of the nature and mechanisms of T regulatory (Treg) cells in the last decade has changed the concept of immune tolerance, that is no longer considered as a mere lack of immune reactivity but as a finely regulated process that requires specific activity of cells, adhesion and secreted molecules. Tregs play a key role in maintenance of self-tolerance and induction of tolerance against ubiquitous innocuous non-self antigens, so preventing the onset of autoimmune diseases and allergies. This review will focus on the Treg response in allergy that is characterized by a down-regulation of allergen specific T cell proliferation and inhibition of both Th1 and Th2 cytokines production. Hence, Treg cells suppress allergen-specific Th1 and Th2 cell responses playing an important role in the physiological immune response to allergens. Further, Treg cells are able to suppress IgE production by B lymphocytes and directly or indirectly inhibit the activity of allergic inflammation effector cells, namely eosinophils, basophils and mastcells. Finally, increasing evidence suggests that Treg cells are also implicated in chronicity development of inflammatory diseases. This appears to happen through a fine interaction they entertain with resident tissue cells and has been particularly highlighted in the study of airways remodeling in asthma. The understanding of the mechanisms underlying allergen tolerance has brought new interest in the development of new allergy treatment, able to target Treg cells, both in allergy prevention and in the therapy of established allergy.